The present disclosure concerns a housing component, comprising a line segment of a hydraulic line with at least one channel and a spatially limited sealing surface enclosing the channel. Furthermore, a method for manufacturing the housing component is specified, in particular for providing a seal on the sealing surface of the channel.
The disclosure is for use in particular with hydraulic blocks that are used to transport a fluid under high pressure, in particular oil. The disclosure is especially for use with valve housing blocks or valves that have had a housing of a cast metallic material until now. The valve is usually bolted onto a control block and is connected to a connection surface by a hydraulic line that is formed in the control block. The fluid channels open at the connecting surfaces of the valves. The openings are encircled by annular grooves, in which separate, elastic sealing rings (in particular for an axial seal) are inserted. The sealing rings are for example formed with an elastomer and/or as a type of O-ring with a predetermined internal diameter and a so-called cross-section diameter. For the application described here, the cross-section diameter preferably lies in the range from approximately 1 mm to 7 mm [millimeter].
With the sealing of the connections of hydraulic valves with O-rings, said O-rings are inserted in recesses on the connections during assembly. Then a cover is put on or the valve is screwed into the assembly at a desired seating position. The O-rings are held in position in operation by the pressing force. During the assembly, there is a risk that the O-rings are (inadvertently) lost and this is only noticed on the test bed or by the customer owing to extraordinary leakage. The insertion of the O-rings is carried out manually, wherein in particular after the insertion of the O-rings still more manual steps, transportation and/or displacement of the valve housing must be carried out, wherein here too the desired accurate positioning of the O-ring can be lost. But just said accurate positioning of the O-rings is necessary if leakage is to be prevented despite the high static pressures occurring with such applications as well as pressure pulses (for example up to 350 bar) during operation.
It has previously been known to manufacture hydraulic blocks from the solid material. In this case, the flow channels and clearances were produced for example by means of drilling and/or grinding. In this case, here too with reference to the O-rings a particularly good, smooth surface (for example RZ,max=4 or 6 μm) on the sealing surface is achieved, which in most cases requires rework. Such manufacturing of hydraulic blocks or housing components with a line segment of a hydraulic line is technically relatively complex and thus also time-intensive and cost-intensive.
In addition, with seal grooves that comprise no internal webs for space reasons, during operation it can occur that an O-ring is pressed or slips in the channel if a back pressure builds up on the inside of the O-ring. Furthermore, it has been determined that owing to an unsteady and dynamic pressure application from the interior, the seal can be subjected to strong alternating stresses, which is accompanied by a repetitive deformation of the seal during operation, which can initiate the risk of damage to the seal and a reduced operating life. Said risk is in particular increased if the seal is already damaged and/or is not aligned accurately during the (manual) assembly.